Gel material for ophthalmic treatment use

A method of treating an ophthalmic disease in a subject, the method comprising:

• administering into an eye of the subject a solution comprising gel precursor clusters, wherein after administration the gel precursor clusters form a hydrogel having a three-dimensional network of crosslinked gel precursor clusters in the eye of the subject,
• wherein the gel precursor clusters have a structure where polymer units are crosslinked at a concentration less than a critical gelation concentration, the gel precursor clusters are in a sol state and have a relationship of G′<G″ where G′ represents a storage elastic modulus and G″ represents a loss elastic modulus, and the gel precursor clusters have a diameter in the range of 10 to 1000 nm,
• wherein the hydrogel has a polymer content of 50 g/L or less, a storage elastic modulus G′ of 1 to 10,000 Pa at a frequency of 1 Hz, and a fractal dimension of 1.5 to 2.5,
• wherein the gel precursor clusters comprise (i) a first polymer unit having one or more nucleophilic functional groups in a side chain or at an end of the first polymer unit, and (ii) a second polymer unit having one or more electrophilic functional groups in a side chain or at an end of the second polymer unit, wherein the first and second polymer units have three- or four-branched polyethylene glycol skeleton,
• wherein the nucleophilic functional group is selected from the group consisting of an amino group and —SH, and the electrophilic functional group is selected from the group consisting of N-hydroxy-succinimidyl (NHS) group and a maleimidyl group,
• wherein the hydrogel comprises the gel precursor clusters that have a diameter in the range of 10 to 1000 nm, and
• wherein the first polymer unit and the second polymer unit have a molecular weight in the range of 5×103 to 5×104 Da.